Two Belgian university professors decided to apply their knowledge of toxicology screenings to the 10 most borrowed books at the Antwerp library. Each book underwent bacteriology and toxicology tests, and the findings reveal that library books are even more germ-covered than you expected.

While the experts found that all 10 books contained traces of cocaine–enough so that people who touched the books wouldn’t feel the effects, but might test positive for the drug–they also found something pretty gross: Fifty Shades of Grey, your weird aunt’s favorite mainstream erotic series, tested positive for traces of the herpes virus.

The professors assured everyone that concentrations of the virus were so minimal that there is no public health risk and it would be impossible for people to contract it by touching the book. Still, something to keep in mind next time you consider taking trashy erotica out of the public library.